Abstract : To accommodate the predicted demand for air traffic service in the year 2000, computer technology must augment human control skills. Preliminary laboratory studies have demonstrated that computer programs can track aircraft, predict their future paths, generate conflict-free clearances, and monitor them for compliance-all automatically. This technology could automate most routine ATC tasks and could change the human role in ATC to that of a system manager. How to make the transition to such a system from the present one and exactly what the future specialist's role would be are the issues addressed by this report. We present three scenarios that delineate a spectrum of transition plans: a Baseline scenario in which the human controller's role is emphasized; and AERA (Automated En Route ATC) scenario in which computers assume the primary control responsibility and perform most ATC functions autonomously; and a Shared Control scenario in which automated, individually invokable modules assist a human specialist who retains the primary responsibility for control.